Evaluation of the Risk of Transmission of Bacterial Biofilms and Clostridium difficile During Gastrointestinal Endoscopy

A New Drying Method of Thermolabile Flexible Endoscope Channels by Laminar and Turbulent Airflow: A Prospective, Randomized-Controlled, Single-Center, Proof-of-Concept Trial

INTRODUCTION

International guidelines suggest different possibilities for drying of endoscopes during reprocessing. Clinical results of these available drying methods are not satisfactory. The aim of this study was to compare the drying cycle of a standard endoscope washer-disinfector (EWD) (standard drying method [SD]) with a shortened mandatory drying by the EWD followed by a special drying device using laminar and turbulent air flow (novel drying method [ND]).

METHODS

Sixty endoscopes (duodenoscopes, colonoscocopes, and gastroscopes) from 3 different manufacturers underwent high-level disinfection and drying depending on the randomization group. Operational time of drying was measured for both groups. Residual fluid in the channels was measured using a laboratory scale. After a 14-day storage period, a sample of the endoscope channels was obtained to determine bacterial contamination.

RESULTS

ND had significantly fewer residual water in endoscope channels (SD: 90% vs ND: 0%; P < 0.001) after high-level disinfection and drying and less bacterial contamination after storage for 14 days (SD: 47% vs ND: 20%; P = 0.028). Time consumed for drying in ND was also significantly shorter (SD: 16 minutes 4 seconds vs ND: 5 minutes 59 seconds; P < 0.001).

DISCUSSION

Drying with a special automatic drying device was superior compared with an EWD's drying program as evidenced by no measurable residual water, reduced microbiological contamination, and a more than 2-fold decrease in operational time. Thus, drying by laminar and turbulent airflow may represent an attractive alternative to the currently used standard approach in the reprocessing process of flexible endoscopes.

Disposable Bronchoscope Model for Simulating Endoscopic Reprocessing and Surveillance Cultures

BACKGROUND Endoscope-associated infections are reported despite following proper reprocessing methods. Microbiological testing can confirm the adequacy of endoscope reprocessing. Multiple controversies related to the method and interpretation of microbiological testing cultures have arisen that make their routine performance a complex target. OBJECTIVE We conducted a pilot study using disposable bronchoscopes (DBs) to simulate different reprocessing times and soaking times and to compare high-level disinfection versus ethylene oxide sterilization. We also reviewed the time to reprocessing and duration of the procedures. METHODS Bronchoscopes were chosen because an alternative disposable scope is commercially available and because bronchoscopes are more prone to delays in processing. Disposable bronchoscopes were contaminated using a liquid bacterial suspension and were then incubated for 1-4 hours. Standard processing and high-level disinfection were performed on 36 endoscopes. Ethylene oxide sterilization was performed on 21 endoscopes. Endoscope cultures were performed using the standard "brush, flush, brush" technique. RESULTS After brushing was performed, a final water-flush culture procedure was the most effective method of detecting bacterial persistence on the disposable scopes. Klebsiella pneumoniae was the most commonly recovered organism after reprocessing. Ethylene oxide sterilization did not result in total elimination of viable bacteria. CONCLUSION Routine endoscopy cultures may be required to assess the adequacy of endoscopic processing. Infect Control Hosp Epidemiol 2017;38:136-142.

The role of biofilms in reprocessing medical devices

Biofilms are communities of microorganisms within extracellular polymeric material attached to surfaces. Within a biofilm, cells have some protection from drying and other stress factors in their environment, including antimicrobial agents. In this article, the challenges to medical device reprocessing posed by biofilms are addressed. Biofilm formation on reusable medical device surfaces is a risk that can be controlled. By ensuring prompt device cleaning and reprocessing either by high-level disinfection or sterilization and proper drying, biofilms will not have a chance to form. Reusable medical devices like flexible endoscopes that are promptly cleaned and disinfected, rinsed and dried pose little risk to patients.